src/share/vm/memory/compactingPermGenGen.cpp

Sat, 01 Dec 2007 00:00:00 +0000

author
duke
date
Sat, 01 Dec 2007 00:00:00 +0000
changeset 435
a61af66fc99e
child 482
2c106685d6d0
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duke@435 1 /*
duke@435 2 * Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
duke@435 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435 21 * have any questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 #include "incls/_precompiled.incl"
duke@435 26 #include "incls/_compactingPermGenGen.cpp.incl"
duke@435 27
duke@435 28
duke@435 29 // Recursively adjust all pointers in an object and all objects by
duke@435 30 // referenced it. Clear marks on objects in order to prevent visiting
duke@435 31 // any object twice.
duke@435 32
duke@435 33 class RecursiveAdjustSharedObjectClosure : public OopClosure {
duke@435 34 public:
duke@435 35 void do_oop(oop* o) {
duke@435 36 oop obj = *o;
duke@435 37 if (obj->is_shared_readwrite()) {
duke@435 38 if (obj->mark()->is_marked()) {
duke@435 39 obj->init_mark(); // Don't revisit this object.
duke@435 40 obj->oop_iterate(this); // Recurse - adjust objects referenced.
duke@435 41 obj->adjust_pointers(); // Adjust this object's references.
duke@435 42
duke@435 43 // Special case: if a class has a read-only constant pool,
duke@435 44 // then the read-write objects referenced by the pool must
duke@435 45 // have their marks reset.
duke@435 46
duke@435 47 if (obj->klass() == Universe::instanceKlassKlassObj()) {
duke@435 48 instanceKlass* ik = instanceKlass::cast((klassOop)obj);
duke@435 49 constantPoolOop cp = ik->constants();
duke@435 50 if (cp->is_shared_readonly()) {
duke@435 51 cp->oop_iterate(this);
duke@435 52 }
duke@435 53 }
duke@435 54 }
duke@435 55 }
duke@435 56 };
duke@435 57 };
duke@435 58
duke@435 59
duke@435 60 // We need to go through all placeholders in the system dictionary and
duke@435 61 // try to resolve them into shared classes. Other threads might be in
duke@435 62 // the process of loading a shared class and have strong roots on
duke@435 63 // their stack to the class without having added the class to the
duke@435 64 // dictionary yet. This means the class will be marked during phase 1
duke@435 65 // but will not be unmarked during the application of the
duke@435 66 // RecursiveAdjustSharedObjectClosure to the SystemDictionary. Note
duke@435 67 // that we must not call find_shared_class with non-read-only symbols
duke@435 68 // as doing so can cause hash codes to be computed, destroying
duke@435 69 // forwarding pointers.
duke@435 70 class TraversePlaceholdersClosure : public OopClosure {
duke@435 71 public:
duke@435 72 void do_oop(oop* o) {
duke@435 73 oop obj = *o;
duke@435 74 if (obj->klass() == Universe::symbolKlassObj() &&
duke@435 75 obj->is_shared_readonly()) {
duke@435 76 symbolHandle sym((symbolOop) obj);
duke@435 77 oop k = SystemDictionary::find_shared_class(sym);
duke@435 78 if (k != NULL) {
duke@435 79 RecursiveAdjustSharedObjectClosure clo;
duke@435 80 clo.do_oop(&k);
duke@435 81 }
duke@435 82 }
duke@435 83 }
duke@435 84 };
duke@435 85
duke@435 86
duke@435 87 void CompactingPermGenGen::initialize_performance_counters() {
duke@435 88
duke@435 89 const char* gen_name = "perm";
duke@435 90
duke@435 91 // Generation Counters - generation 2, 1 subspace
duke@435 92 _gen_counters = new GenerationCounters(gen_name, 2, 1, &_virtual_space);
duke@435 93
duke@435 94 _space_counters = new CSpaceCounters(gen_name, 0,
duke@435 95 _virtual_space.reserved_size(),
duke@435 96 _the_space, _gen_counters);
duke@435 97 }
duke@435 98
duke@435 99 void CompactingPermGenGen::update_counters() {
duke@435 100 if (UsePerfData) {
duke@435 101 _space_counters->update_all();
duke@435 102 _gen_counters->update_all();
duke@435 103 }
duke@435 104 }
duke@435 105
duke@435 106
duke@435 107 CompactingPermGenGen::CompactingPermGenGen(ReservedSpace rs,
duke@435 108 ReservedSpace shared_rs,
duke@435 109 size_t initial_byte_size,
duke@435 110 int level, GenRemSet* remset,
duke@435 111 ContiguousSpace* space,
duke@435 112 PermanentGenerationSpec* spec_) :
duke@435 113 OneContigSpaceCardGeneration(rs, initial_byte_size, MinPermHeapExpansion,
duke@435 114 level, remset, space) {
duke@435 115
duke@435 116 set_spec(spec_);
duke@435 117 if (!UseSharedSpaces && !DumpSharedSpaces) {
duke@435 118 spec()->disable_sharing();
duke@435 119 }
duke@435 120
duke@435 121 // Break virtual space into address ranges for all spaces.
duke@435 122
duke@435 123 if (spec()->enable_shared_spaces()) {
duke@435 124 shared_end = (HeapWord*)(shared_rs.base() + shared_rs.size());
duke@435 125 misccode_end = shared_end;
duke@435 126 misccode_bottom = misccode_end - heap_word_size(spec()->misc_code_size());
duke@435 127 miscdata_end = misccode_bottom;
duke@435 128 miscdata_bottom = miscdata_end - heap_word_size(spec()->misc_data_size());
duke@435 129 readwrite_end = miscdata_bottom;
duke@435 130 readwrite_bottom =
duke@435 131 readwrite_end - heap_word_size(spec()->read_write_size());
duke@435 132 readonly_end = readwrite_bottom;
duke@435 133 readonly_bottom =
duke@435 134 readonly_end - heap_word_size(spec()->read_only_size());
duke@435 135 shared_bottom = readonly_bottom;
duke@435 136 unshared_end = shared_bottom;
duke@435 137 assert((char*)shared_bottom == shared_rs.base(), "shared space mismatch");
duke@435 138 } else {
duke@435 139 shared_end = (HeapWord*)(rs.base() + rs.size());
duke@435 140 misccode_end = shared_end;
duke@435 141 misccode_bottom = shared_end;
duke@435 142 miscdata_end = shared_end;
duke@435 143 miscdata_bottom = shared_end;
duke@435 144 readwrite_end = shared_end;
duke@435 145 readwrite_bottom = shared_end;
duke@435 146 readonly_end = shared_end;
duke@435 147 readonly_bottom = shared_end;
duke@435 148 shared_bottom = shared_end;
duke@435 149 unshared_end = shared_bottom;
duke@435 150 }
duke@435 151 unshared_bottom = (HeapWord*) rs.base();
duke@435 152
duke@435 153 // Verify shared and unshared spaces adjacent.
duke@435 154 assert((char*)shared_bottom == rs.base()+rs.size(), "shared space mismatch");
duke@435 155 assert(unshared_end > unshared_bottom, "shared space mismatch");
duke@435 156
duke@435 157 // Split reserved memory into pieces.
duke@435 158
duke@435 159 ReservedSpace ro_rs = shared_rs.first_part(spec()->read_only_size(),
duke@435 160 UseSharedSpaces);
duke@435 161 ReservedSpace tmp_rs1 = shared_rs.last_part(spec()->read_only_size());
duke@435 162 ReservedSpace rw_rs = tmp_rs1.first_part(spec()->read_write_size(),
duke@435 163 UseSharedSpaces);
duke@435 164 ReservedSpace tmp_rs2 = tmp_rs1.last_part(spec()->read_write_size());
duke@435 165 ReservedSpace md_rs = tmp_rs2.first_part(spec()->misc_data_size(),
duke@435 166 UseSharedSpaces);
duke@435 167 ReservedSpace mc_rs = tmp_rs2.last_part(spec()->misc_data_size());
duke@435 168
duke@435 169 _shared_space_size = spec()->read_only_size()
duke@435 170 + spec()->read_write_size()
duke@435 171 + spec()->misc_data_size()
duke@435 172 + spec()->misc_code_size();
duke@435 173
duke@435 174 // Allocate the unshared (default) space.
duke@435 175 _the_space = new ContigPermSpace(_bts,
duke@435 176 MemRegion(unshared_bottom, heap_word_size(initial_byte_size)));
duke@435 177 if (_the_space == NULL)
duke@435 178 vm_exit_during_initialization("Could not allocate an unshared"
duke@435 179 " CompactingPermGen Space");
duke@435 180
duke@435 181 // Allocate shared spaces
duke@435 182 if (spec()->enable_shared_spaces()) {
duke@435 183
duke@435 184 // If mapping a shared file, the space is not committed, don't
duke@435 185 // mangle.
duke@435 186 NOT_PRODUCT(bool old_ZapUnusedHeapArea = ZapUnusedHeapArea;)
duke@435 187 NOT_PRODUCT(if (UseSharedSpaces) ZapUnusedHeapArea = false;)
duke@435 188
duke@435 189 // Commit the memory behind the shared spaces if dumping (not
duke@435 190 // mapping).
duke@435 191 if (DumpSharedSpaces) {
duke@435 192 _ro_vs.initialize(ro_rs, spec()->read_only_size());
duke@435 193 _rw_vs.initialize(rw_rs, spec()->read_write_size());
duke@435 194 _md_vs.initialize(md_rs, spec()->misc_data_size());
duke@435 195 _mc_vs.initialize(mc_rs, spec()->misc_code_size());
duke@435 196 }
duke@435 197
duke@435 198 // Allocate the shared spaces.
duke@435 199 _ro_bts = new BlockOffsetSharedArray(
duke@435 200 MemRegion(readonly_bottom,
duke@435 201 heap_word_size(spec()->read_only_size())),
duke@435 202 heap_word_size(spec()->read_only_size()));
duke@435 203 _ro_space = new OffsetTableContigSpace(_ro_bts,
duke@435 204 MemRegion(readonly_bottom, readonly_end));
duke@435 205 _rw_bts = new BlockOffsetSharedArray(
duke@435 206 MemRegion(readwrite_bottom,
duke@435 207 heap_word_size(spec()->read_write_size())),
duke@435 208 heap_word_size(spec()->read_write_size()));
duke@435 209 _rw_space = new OffsetTableContigSpace(_rw_bts,
duke@435 210 MemRegion(readwrite_bottom, readwrite_end));
duke@435 211
duke@435 212 // Restore mangling flag.
duke@435 213 NOT_PRODUCT(ZapUnusedHeapArea = old_ZapUnusedHeapArea;)
duke@435 214
duke@435 215 if (_ro_space == NULL || _rw_space == NULL)
duke@435 216 vm_exit_during_initialization("Could not allocate a shared space");
duke@435 217
duke@435 218 // Cover both shared spaces entirely with cards.
duke@435 219 _rs->resize_covered_region(MemRegion(readonly_bottom, readwrite_end));
duke@435 220
duke@435 221 if (UseSharedSpaces) {
duke@435 222
duke@435 223 // Map in the regions in the shared file.
duke@435 224 FileMapInfo* mapinfo = FileMapInfo::current_info();
duke@435 225 size_t image_alignment = mapinfo->alignment();
duke@435 226 CollectedHeap* ch = Universe::heap();
duke@435 227 if ((!mapinfo->map_space(ro, ro_rs, _ro_space)) ||
duke@435 228 (!mapinfo->map_space(rw, rw_rs, _rw_space)) ||
duke@435 229 (!mapinfo->map_space(md, md_rs, NULL)) ||
duke@435 230 (!mapinfo->map_space(mc, mc_rs, NULL)) ||
duke@435 231 // check the alignment constraints
duke@435 232 (ch == NULL || ch->kind() != CollectedHeap::GenCollectedHeap ||
duke@435 233 image_alignment !=
duke@435 234 ((GenCollectedHeap*)ch)->gen_policy()->max_alignment())) {
duke@435 235 // Base addresses didn't match; skip sharing, but continue
duke@435 236 shared_rs.release();
duke@435 237 spec()->disable_sharing();
duke@435 238 // If -Xshare:on is specified, print out the error message and exit VM,
duke@435 239 // otherwise, set UseSharedSpaces to false and continue.
duke@435 240 if (RequireSharedSpaces) {
duke@435 241 vm_exit_during_initialization("Unable to use shared archive.", NULL);
duke@435 242 } else {
duke@435 243 FLAG_SET_DEFAULT(UseSharedSpaces, false);
duke@435 244 }
duke@435 245
duke@435 246 // Note: freeing the block offset array objects does not
duke@435 247 // currently free up the underlying storage.
duke@435 248 delete _ro_bts;
duke@435 249 _ro_bts = NULL;
duke@435 250 delete _ro_space;
duke@435 251 _ro_space = NULL;
duke@435 252 delete _rw_bts;
duke@435 253 _rw_bts = NULL;
duke@435 254 delete _rw_space;
duke@435 255 _rw_space = NULL;
duke@435 256 shared_end = (HeapWord*)(rs.base() + rs.size());
duke@435 257 _rs->resize_covered_region(MemRegion(shared_bottom, shared_bottom));
duke@435 258 }
duke@435 259 }
duke@435 260
duke@435 261 // Reserved region includes shared spaces for oop.is_in_reserved().
duke@435 262 _reserved.set_end(shared_end);
duke@435 263
duke@435 264 } else {
duke@435 265 _ro_space = NULL;
duke@435 266 _rw_space = NULL;
duke@435 267 }
duke@435 268 }
duke@435 269
duke@435 270
duke@435 271 // Do a complete scan of the shared read write space to catch all
duke@435 272 // objects which contain references to any younger generation. Forward
duke@435 273 // the pointers. Avoid space_iterate, as actually visiting all the
duke@435 274 // objects in the space will page in more objects than we need.
duke@435 275 // Instead, use the system dictionary as strong roots into the read
duke@435 276 // write space.
duke@435 277
duke@435 278 void CompactingPermGenGen::pre_adjust_pointers() {
duke@435 279 if (spec()->enable_shared_spaces()) {
duke@435 280 RecursiveAdjustSharedObjectClosure blk;
duke@435 281 Universe::oops_do(&blk);
duke@435 282 StringTable::oops_do(&blk);
duke@435 283 SystemDictionary::always_strong_classes_do(&blk);
duke@435 284 TraversePlaceholdersClosure tpc;
duke@435 285 SystemDictionary::placeholders_do(&tpc);
duke@435 286 }
duke@435 287 }
duke@435 288
duke@435 289
duke@435 290 #ifdef ASSERT
duke@435 291 class VerifyMarksClearedClosure : public ObjectClosure {
duke@435 292 public:
duke@435 293 void do_object(oop obj) {
duke@435 294 assert(SharedSkipVerify || !obj->mark()->is_marked(),
duke@435 295 "Shared oop still marked?");
duke@435 296 }
duke@435 297 };
duke@435 298 #endif
duke@435 299
duke@435 300
duke@435 301 void CompactingPermGenGen::post_compact() {
duke@435 302 #ifdef ASSERT
duke@435 303 if (!SharedSkipVerify && spec()->enable_shared_spaces()) {
duke@435 304 VerifyMarksClearedClosure blk;
duke@435 305 rw_space()->object_iterate(&blk);
duke@435 306 }
duke@435 307 #endif
duke@435 308 }
duke@435 309
duke@435 310
duke@435 311 void CompactingPermGenGen::space_iterate(SpaceClosure* blk, bool usedOnly) {
duke@435 312 OneContigSpaceCardGeneration::space_iterate(blk, usedOnly);
duke@435 313 if (spec()->enable_shared_spaces()) {
duke@435 314 #ifdef PRODUCT
duke@435 315 // Making the rw_space walkable will page in the entire space, and
duke@435 316 // is to be avoided. However, this is required for Verify options.
duke@435 317 ShouldNotReachHere();
duke@435 318 #endif
duke@435 319
duke@435 320 blk->do_space(ro_space());
duke@435 321 blk->do_space(rw_space());
duke@435 322 }
duke@435 323 }
duke@435 324
duke@435 325
duke@435 326 void CompactingPermGenGen::print_on(outputStream* st) const {
duke@435 327 OneContigSpaceCardGeneration::print_on(st);
duke@435 328 if (spec()->enable_shared_spaces()) {
duke@435 329 st->print(" ro");
duke@435 330 ro_space()->print_on(st);
duke@435 331 st->print(" rw");
duke@435 332 rw_space()->print_on(st);
duke@435 333 } else {
duke@435 334 st->print_cr("No shared spaces configured.");
duke@435 335 }
duke@435 336 }
duke@435 337
duke@435 338
duke@435 339 // References from the perm gen to the younger generation objects may
duke@435 340 // occur in static fields in Java classes or in constant pool references
duke@435 341 // to String objects.
duke@435 342
duke@435 343 void CompactingPermGenGen::younger_refs_iterate(OopsInGenClosure* blk) {
duke@435 344 OneContigSpaceCardGeneration::younger_refs_iterate(blk);
duke@435 345 if (spec()->enable_shared_spaces()) {
duke@435 346 blk->set_generation(this);
duke@435 347 // ro_space has no younger gen refs.
duke@435 348 _rs->younger_refs_in_space_iterate(rw_space(), blk);
duke@435 349 blk->reset_generation();
duke@435 350 }
duke@435 351 }
duke@435 352
duke@435 353
duke@435 354 // Shared spaces are addressed in pre_adjust_pointers.
duke@435 355 void CompactingPermGenGen::adjust_pointers() {
duke@435 356 the_space()->adjust_pointers();
duke@435 357 }
duke@435 358
duke@435 359
duke@435 360 void CompactingPermGenGen::compact() {
duke@435 361 the_space()->compact();
duke@435 362 }
duke@435 363
duke@435 364
duke@435 365 size_t CompactingPermGenGen::contiguous_available() const {
duke@435 366 // Don't include shared spaces.
duke@435 367 return OneContigSpaceCardGeneration::contiguous_available()
duke@435 368 - _shared_space_size;
duke@435 369 }
duke@435 370
duke@435 371 size_t CompactingPermGenGen::max_capacity() const {
duke@435 372 // Don't include shared spaces.
duke@435 373 assert(UseSharedSpaces || (_shared_space_size == 0),
duke@435 374 "If not used, the size of shared spaces should be 0");
duke@435 375 return OneContigSpaceCardGeneration::max_capacity()
duke@435 376 - _shared_space_size;
duke@435 377 }
duke@435 378
duke@435 379
duke@435 380
duke@435 381 bool CompactingPermGenGen::grow_by(size_t bytes) {
duke@435 382 // Don't allow _virtual_size to expand into shared spaces.
duke@435 383 size_t max_bytes = _virtual_space.uncommitted_size() - _shared_space_size;
duke@435 384 if (bytes > _shared_space_size) {
duke@435 385 bytes = _shared_space_size;
duke@435 386 }
duke@435 387 return OneContigSpaceCardGeneration::grow_by(bytes);
duke@435 388 }
duke@435 389
duke@435 390
duke@435 391 void CompactingPermGenGen::grow_to_reserved() {
duke@435 392 // Don't allow _virtual_size to expand into shared spaces.
duke@435 393 if (_virtual_space.uncommitted_size() > _shared_space_size) {
duke@435 394 size_t remaining_bytes =
duke@435 395 _virtual_space.uncommitted_size() - _shared_space_size;
duke@435 396 bool success = OneContigSpaceCardGeneration::grow_by(remaining_bytes);
duke@435 397 DEBUG_ONLY(if (!success) warning("grow to reserved failed");)
duke@435 398 }
duke@435 399 }
duke@435 400
duke@435 401
duke@435 402 // No young generation references, clear this generation's main space's
duke@435 403 // card table entries. Do NOT clear the card table entries for the
duke@435 404 // read-only space (always clear) or the read-write space (valuable
duke@435 405 // information).
duke@435 406
duke@435 407 void CompactingPermGenGen::clear_remembered_set() {
duke@435 408 _rs->clear(MemRegion(the_space()->bottom(), the_space()->end()));
duke@435 409 }
duke@435 410
duke@435 411
duke@435 412 // Objects in this generation's main space may have moved, invalidate
duke@435 413 // that space's cards. Do NOT invalidate the card table entries for the
duke@435 414 // read-only or read-write spaces, as those objects never move.
duke@435 415
duke@435 416 void CompactingPermGenGen::invalidate_remembered_set() {
duke@435 417 _rs->invalidate(used_region());
duke@435 418 }
duke@435 419
duke@435 420
duke@435 421 void CompactingPermGenGen::verify(bool allow_dirty) {
duke@435 422 the_space()->verify(allow_dirty);
duke@435 423 if (!SharedSkipVerify && spec()->enable_shared_spaces()) {
duke@435 424 ro_space()->verify(allow_dirty);
duke@435 425 rw_space()->verify(allow_dirty);
duke@435 426 }
duke@435 427 }
duke@435 428
duke@435 429
duke@435 430 HeapWord* CompactingPermGenGen::unshared_bottom;
duke@435 431 HeapWord* CompactingPermGenGen::unshared_end;
duke@435 432 HeapWord* CompactingPermGenGen::shared_bottom;
duke@435 433 HeapWord* CompactingPermGenGen::shared_end;
duke@435 434 HeapWord* CompactingPermGenGen::readonly_bottom;
duke@435 435 HeapWord* CompactingPermGenGen::readonly_end;
duke@435 436 HeapWord* CompactingPermGenGen::readwrite_bottom;
duke@435 437 HeapWord* CompactingPermGenGen::readwrite_end;
duke@435 438 HeapWord* CompactingPermGenGen::miscdata_bottom;
duke@435 439 HeapWord* CompactingPermGenGen::miscdata_end;
duke@435 440 HeapWord* CompactingPermGenGen::misccode_bottom;
duke@435 441 HeapWord* CompactingPermGenGen::misccode_end;
duke@435 442
duke@435 443 // JVM/TI RedefineClasses() support:
duke@435 444 bool CompactingPermGenGen::remap_shared_readonly_as_readwrite() {
duke@435 445 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
duke@435 446
duke@435 447 if (UseSharedSpaces) {
duke@435 448 // remap the shared readonly space to shared readwrite, private
duke@435 449 FileMapInfo* mapinfo = FileMapInfo::current_info();
duke@435 450 if (!mapinfo->remap_shared_readonly_as_readwrite()) {
duke@435 451 return false;
duke@435 452 }
duke@435 453 }
duke@435 454 return true;
duke@435 455 }
duke@435 456
duke@435 457 void** CompactingPermGenGen::_vtbl_list;

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